As a flat panel display technology, field emission display (FED) is of great potential. Operating voltage of FED is lower than that of the cathode ray tube (CRT), typically less than 5 kV, and the operating current density is relatively large, generally in a range of 10-100 μA·cm−2. Thus, the requirements for luminescent material of an FED of luminescent material is increasing, such as better chromaticity, higher luminescent efficiency at low voltage, and no luminance saturation at high current densities.
Currently, research of field emission displays luminescent materials mainly focuses on two aspects: First, to use and improve the existing cathode ray tube luminescent materials; Second, to find a new luminescent material. A primary commercially available luminescent material for CRT is oxide of sulfur. When an oxide of sulfur is used to prepare an FED, the luminescent intensity of FED will decrease because the sulfur may react with other elements existing in the cathode, such as molybdenum, silicon or germanium, thus weakening electron emissions.